I wasn't aware this had a name, but I've proposed this in terms of families. Most people come from larger families than they have. That is, for most people, the

I wasn't aware this had a name, but I've proposed this in terms of families. Most people come from larger families than they have. That is, for most people, the number of brothers and sisters plus one (for the person we're talking about) is greater than the number of children that person will eventually have. Or at least it can be, even in a growing population. Consider a family with four children. Alice, Bob, Charlie and Dave. Assume that Alice goes on to have four children of her own, and her brothers have none. So Alice has exactly as many children as brothers + sisters + 1. But 3/4 of the children in the original family have fewer children than siblings + 1. It's a consequence of the counting being proportional to the size of the family. A family with 4 children gets counted four times, a family with 1 child gets counted only once. It's more complicated to show with friendships because the graph isn't directed, but it holds for the same reason. A social butterfly with lots of friends gets counted for each of his or her friends. Someone with few friends only gets counted for those few friends.